Colon polyps are small growths on the inside of the
colon. They develop from normal cells that have started to divide and grow
at an increased
rate.

Notice the raised appearance of this polyp. It's growing more quickly
than the surrounding colon.

Polyps can be
classified by what type of cells they develop from, or by their
appearance.

This is a picture
of a "pedunculated" polyp. This polyp has a stalk beneath it. It is
a large polyp which was causing the person to have bright red blood with bowel
movements.

This is a picture of a flat or "sessile" polyp.
These polyps can be difficult to spot if the colon is not properly cleaned.

Depending on what
cells a polyp has develped from, some polyps will grow rather quickly and carry
a greater risk of developing colon cancer. Any polyps removed from the
colon need to be examined under a microscope to determine if they
carry this increased risk. Your physician should meet with you after
your colonoscopy to discuss these results.

These are some examples of
polyps classified according to their cellular type:

1. Hyperplastic
polyps - Low risk of developing into a colon
cancer.

2. Tubular adenomas - Slightly
increased risk of colon cancer.

3. Tubular-villous adenomas -
More of an increased risk of colon cancer.

4. Villous adenomas - High risk of
developing into colon cancer.

5. Serrated adenomas - Highest risk of
developing into colon cancer.

Pictures of
various polyps

This is a flat polyp which is raised up slightly.
It does not have a stalk like a "pedunculated" polyp. We would call this a
"semi-sessile" polyp. After examining this polyp under a microscope, it
was decided that it was a "villous adenoma". It carries a high risk
of developing into colon cancer.

These are two small polyps. They represent "sessile", or flat,
polyps which can be difficult to spot (especially if the colon has not been
cleansed well). These polyps were found to be "serrated adenomas" with a
high risk of developing into colon cancer.

This polyp is also a "semi-sessile" polyp which was
difficult to spot due to the fact that it was growing behind a fold. It
was found to be a "tubular adenoma" with a lower risk of developing into
colon cancer.

As you can see
from the above pictures it can be difficult to determine the risk a polyp
carries of developing into colon cancer from appearance alone. Only your
physician can determine when you may need a repeat colonoscopy based on the type,
appearance, and number of polyps found.